The present invention relates in general to electrical connectors. More particularly, the present invention relates to electrical connectors having densely packed contact members capable of passing signals while minimizing crosstalk between adjacent contact members, especially at high frequencies.
In electronic equipment, there is a need for electrical connectors providing connections in signal paths, and often the signal paths are so closely spaced that difficulties arise from interference between signals being transmitted along adjacent paths.
In order to minimize such difficulties it is known to provide grounding connections in such connectors, such connections serving in effect to filter out undesired interference between signal paths.
However, mere grounding is not always sufficient, and this is particularly so in connectors in which contacts constituting the signal paths through the connector extend through sharp angles, because interference between adjacent signal paths is a particularly significant problem in such connectors.
In many situations where electrical signals are being carried among separate subassemblies of complex electrical and electronic devices, reduced size contributes greatly to the usefulness or convenience of the devices or of certain portions of them. To that end, extremely small conductors are now available, and it is practical to manufacture very closely spaced terminal pads accurately located on circuit boards or the like. It is therefore desirable to have a connector of reduced size, to interconnect circuit boards repeatedly, easily, and reliably, and with a minimum adverse effect on electrical signal transmission in a circuit including such a connector.
In high speed backplane applications, low crosstalk between signal currents passing through the connector is desirable. Low crosstalk allows the electronics to switch at higher frequencies yet maintain signal integrity. Additionally, maximizing signal density is also desirable. High density increases the number of circuits that can be routed through the connector. However, as the density of devices and signals is increased, the problem of crosstalk increases. Moreover, as frequencies are increased, the crosstalk is increased.
Therefore, a need exists for electrical connectors of increased density, yet capable of maintaining signal integrity, especially at high frequencies. However, achieving these requirements must be in the context of smaller connectors that can be manufactured at low costs.
The present invention is directed to a connector for mounting to a circuit substrate comprising a housing and a connector pair supported by the housing. The connector pair includes a header connector having an electrically conductive connector housing, an opening in which an insulator element having a pin opening is disposed, a signal pin extending through the pin opening in the insulator element and through the connector housing and separated from the connector housing by the insulator element, and a raised ground surface adjacent the insulator element and the signal pin. The connector pair also includes a socket connector, having a signal receptacle contact, a ground receptacle contacts and a dielectric separating element separating the signal contact and the ground contact from one another, so that, in mated condition, the signal contact mechanically connects and electrically contacts with the signal pin, and the ground contact mechanically connects and electrically contacts with the raised cylindrical ground surface.
The present invention, is also directed to contact terminals formed of a base metallic layer capable of being shaped into a contact structure, a thin film dielectric material disposed on the base layer and a contact layer of conductive material disposed on the dielectric layer. The base layer may form a ground or shield structure and the conductive material may form the signal contact.
The present invention also concerns a socket connector comprising a receptacle housing and contact terminals in the housing. The signal receptacle contact is a dual cantilevered receptacle contact, and the ground receptacle contact is a dual cantilevered receptacle contact. The dual cantilevered ground contact is external to the dual cantilevered signal contact.
This invention further contemplates a socket connector having a contact terminal wherein the signal receptacle contact is a dual cantilevered signal contact, and the ground receptacle contact is a single cantilevered receptacle contact. The single cantilevered ground receptacle contact is offset 90 degrees to the dual cantilevered signal receptacle contact.
The foregoing and other aspects of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.